I was thinking I would switch back to Mobil 1 on my next oil change for my 97 evo motor. The previous owner ran synthetic, then switched back to conventional. I do have a small leak from somewhere, havent figured out exactly where yet. I'll get 1 or 2 drops of oil on the ground after a ride. I know if I switch back to Mobil 1 that it will probably get worse, but my question is how much worse? The engine has 50,000 miles on it. Runs great other than the small leak. The other question is does everyone run synthetic in trannie and primary also?